What Do We Know About Chagas Disease in the United States?

Chagas disease, caused by the parasite Trypanosoma cruzi, affects more than 5 million people worldwide leading to serious heart and gastrointestinal disease in a proportion of chronically infected patients. Important modes of transmission include vector-borne, congenital, and via blood transfusion or organ transplant from an infected donor. Vector-borne transmission of Chagas disease occurs in the Americas, including the southern half of North America, where the specific vector insects (triatomines), T. cruzi, and infected reservoir mammalian hosts are found. In the United States, there are estimated to be at least 300,000 cases of chronic Chagas disease among people originally from countries of Latin America where Chagas disease is endemic. Fewer than 30 cases of locally acquired infection have been documented in the United States, although a sylvatic transmission cycle has been known to exist in this country for at least a century. Studies defining risks for locally acquired infection and effective prevention strategies are needed to help prevent domestic transmission of T. cruzi To help address Chagas disease in the United States, improved health-care provider awareness and knowledge, better tools for screening and diagnosing patients, and wider availability of treatment drugs are needed.

Neglected parasitic infections in the United States: toxoplasmosis

Toxoplasma gondii is a leading cause of severe foodborne illness in the United States. Population-based studies have found T. gondii infection to be more prevalent in racial/ethnic minority and socioeconomically disadvantaged groups. Soil contaminated with cat feces, undercooked meat, and congenital transmission are the principal sources of infection. Toxoplasmosis-associated illnesses include congenital neurologic and ocular disease; acquired illness in immunocompetent persons, most notably ocular disease; and encephalitis or disseminated disease in immunosuppressed persons. The association of T. gondii infection with risk for mental illness is intriguing and requires further research. Reduction of T. gondii in meat, improvements in hygiene and food preparation practices, and reduction of environmental contamination can prevent toxoplasmosis, but more research is needed on how to implement these measures. In addition, screening and treatment may help prevent toxoplasmosis or reduce the severity of disease in some settings.

Neglected parasitic infections in the United States: toxocariasis

Toxocariasis is a preventable parasitic disease that is caused by the dog and cat roundworms Toxocara cani and T. cati, respectively. Humans become infected when they accidently ingest infectious Toxocara eggs commonly found in contaminated soil; children are most often affected. Clinical manifestations of Toxocara infection in humans include ocular toxocariasis and visceral toxocariasis. Although infection with Toxocara can cause devastating disease, the burden of toxocariasis in the United States population remains unknown. In addition, risk factors for acquiring infection need to be better defined, and research needs to be conducted to better understand the pathophysiology and clinical course of toxocariasis. Development of diagnostic tests would enable clinicians to detect active infection, and determination of optimal drug regiments would ensure patients were appropriately treated. Addressing these public health gaps is necessary to understand and address the impact of toxocariasis in the United States.

Clinical, epidemiologic, histopathologic and molecular features of an unexplained dermopathy

BACKGROUND

Morgellons is a poorly characterized constellation of symptoms, with the primary manifestations involving the skin. We conducted an investigation of this unexplained dermopathy to characterize the clinical and epidemiologic features and explore potential etiologies.

METHODS

A descriptive study was conducted among persons at least 13 years of age and enrolled in Kaiser Permanente Northern California (KPNC) during 2006-2008. A case was defined as the self-reported emergence of fibers or materials from the skin accompanied by skin lesions and/or disturbing skin sensations. We collected detailed epidemiologic data, performed clinical evaluations and geospatial analyses and analyzed materials collected from participants' skin.

RESULTS

We identified 115 case-patients. The prevalence was 3.65 (95% CI = 2.98, 4.40) cases per 100,000 enrollees. There was no clustering of cases within the 13-county KPNC catchment area (p = .113). Case-patients had a median age of 52 years (range: 17-93) and were primarily female (77%) and Caucasian (77%). Multi-system complaints were common; 70% reported chronic fatigue and 54% rated their overall health as fair or poor with mean Physical Component Scores and Mental Component Scores of 36.63 (SD = 12.9) and 35.45 (SD = 12.89), respectively. Cognitive deficits were detected in 59% of case-patients and 63% had evidence of clinically significant somatic complaints; 50% had drugs detected in hair samples and 78% reported exposure to solvents. Solar elastosis was the most common histopathologic abnormality (51% of biopsies); skin lesions were most consistent with arthropod bites or chronic excoriations. No parasites or mycobacteria were detected. Most materials collected from participants' skin were composed of cellulose, likely of cotton origin.

CONCLUSIONS

This unexplained dermopathy was rare among this population of Northern California residents, but associated with significantly reduced health-related quality of life. No common underlying medical condition or infectious source was identified, similar to more commonly recognized conditions such as delusional infestation.

Doxycycline for malaria chemoprophylaxis and treatment: report from the CDC expert meeting on malaria chemoprophylaxis

Doxycycline, a synthetically derived tetracycline, is a partially efficacious causal prophylactic (liver stage of Plasmodium) drug and a slow acting blood schizontocidal agent highly effective for the prevention of malaria. When used in conjunction with a fast acting schizontocidal agent, it is also highly effective for malaria treatment. Doxycycline is especially useful as a prophylaxis in areas with chloroquine and multidrug-resistant Plasmodium falciparum malaria. Although not recommended for pregnant women and children < 8 years of age, severe adverse events are rarely reported for doxycycline. This report examines the evidence behind current recommendations for the use of doxycycline for malaria and summarizes the available literature on its safety and tolerability.

Associations between peripheral Plasmodium falciparum malaria parasitemia, human immunodeficiency virus, and concurrent helminthic infection among pregnant women in Malawi

Approximately 2 billion persons worldwide are infected with schistosomiasis and soil-transmitted helminths (STH), many in areas where endemic malaria transmission coexists. Few data exist on associations between these infections. Nested within a larger clinical trial, primigravid and secundigravid women provided blood samples for human immunodeficiency virus (HIV) testing and peripheral malaria films and stool and urine for evaluation of STH and Schistosoma spp. during their initial antenatal clinic visit. The most common parasitic infections were malaria (37.6%), S. haematobium (32.3%), and hookworm (14.4%); 14.2% of women were HIV-infected. S. haematobium infection was associated with lower malarial parasite densities (344 versus 557 parasites/μL blood; P < 0.05). In multivariate analysis, HIV and hookworm infection were independently associated with malaria infection (adjusted odds ratio = 1.9 and 95% confidence interval = 1.2-3.0 for HIV; adjusted odds ratio = 1.9 and 95% confidence interval = 1.03-3.5 for hookworm). Concurrent helminthic infection had both positive and negative effects on malaria parasitemia among pregnant women in Malawi.

Pharmacokinetics of sulfadoxine-pyrimethamine in HIV-infected and uninfected pregnant women in Western Kenya

BACKGROUND

Sulfadoxine-pyrimethamine (SP) is among the most commonly used antimalarial drugs during pregnancy, yet the pharmacokinetics of SP are unknown in pregnant women. HIV-infected (HIV(+)) women require more frequent doses of intermittent preventive therapy with SP than do HIV-uninfected (HIV(-)) women. We investigated whether this reflects their impaired immunity or an HIV-associated alteration in the disposition of SP.

METHODS

Seventeen pregnant HIV(-) women and 16 pregnant HIV(+) women received a dose of 1500 mg of sulfadoxine and 75 mg of pyrimethamine. Five HIV(-) and 6 HIV(+) postpartum women returned 2-3 months after delivery for another dose. The pharmacokinetics of sulfadoxine and pyrimethamine were compared between these groups.

RESULTS

HIV status did not affect the area under the curve (AUC(0-->infinity)) or the half-lives of sulfadoxine or pyrimethamine in prepartum or postpartum women, although partum status did have a significant affect on sulfadoxine pharmacokinetics. Among prepartum women, the median half-life for sulfadoxine was significantly shorter than that observed in postpartum women (148 vs 256 h; P<.001), and the median AUC(0-->infinity) was ~40% lower (22,816 vs 40,106 microg/mL/h, P<.001). HIV status and partum status did not show any significant influence on pyrimethamine pharmacokinetics.

CONCLUSION

Pregnancy significantly modifies the disposition of SP, whereas HIV status has little influence on pharmacokinetic parameters in pregnant women.

Safety and toxicity of sulfadoxine/pyrimethamine: implications for malaria prevention in pregnancy using intermittent preventive treatment

Plasmodium falciparum infection during pregnancy is strongly associated with maternal anaemia and low birth weight, contributing to substantial morbidity and mortality in sub-Saharan Africa. Intermittent preventive treatment in pregnancy with sulfadoxine/pyrimethamine (IPTp-SP) has been one of the most effective approaches to reduce the burden of malaria during pregnancy in Africa. IPTp-SP is based on administering >or=2 treatment doses of sulfadoxine/pyrimethamine to pregnant women at predefined intervals after quickening (around 18-20 weeks). Randomised, controlled trials have demonstrated decreased rates of maternal anaemia and low birth weight with this approach. The WHO currently recommends IPTp-SP in malaria-endemic areas of sub-Saharan Africa. However, implementation has been suboptimal in part because of concerns of potential drug toxicities. This review evaluates the toxicity data of sulfadoxine/pyrimethamine, including severe cutaneous adverse reactions, teratogenicity and alterations in bilirubin metabolism. Weekly sulfadoxine/pyrimethamine prophylaxis is associated with rare but potentially fatal cutaneous reactions. Fortunately, sulfadoxine/pyrimethamine use in IPTp programmes in Africa, with 2-4 treatment doses over 6 months, has been well tolerated in multiple IPTp trials. However, sulfadoxine/pyrimethamine should not be administered concurrently with cotrimoxazole given their redundant mechanisms of action and synergistic worsening of adverse drug reactions. Therefore, HIV-infected pregnant women in malaria endemic areas who are already receiving cotrimoxazole prophylaxis should not also receive IPTp-SP. Although folate antagonist use in the first trimester is associated with neural tube defects, large case-control studies have demonstrated that sulfadoxine/pyrimethamine administered as IPTp (exclusively in the second and third trimesters and after organogenesis) does not result in an increased risk of teratogenesis. Folic acid supplementation is recommended for all pregnant women to reduce the rate of congenital anomalies but high doses of folic acid (5 mg/day) may interfere with the antimalarial efficacy of sulfadoxine/pyrimethamine. However, the recommended standard dose of folic acid supplementation (0.4 mg/day) does not affect antimalarial efficacy and may provide the optimal balance to prevent neural tube defects and maintain the effectiveness of IPTp-SP. No clinical association between sulfadoxine/pyrimethamine use and kernicterus has been reported despite the extensive use of sulfadoxine/pyrimethamine and related compounds to treat maternal malaria and congenital toxoplasmosis in near-term pregnant women and newborns. Although few drugs in pregnancy can be considered completely safe, sulfadoxine/pyrimethamine - when delivered as IPTp - has a favourable safety profile. Improved pharmacovigilance programmes throughout Africa are now needed to confirm its safety as access to IPTp-SP increases. Given the documented benefits of IPTp-SP in malaria endemic areas of Africa, access to this treatment for pregnant women should continue to expand.

Treatment of malaria in the United States: a systematic review

CONTEXT

Many US clinicians and laboratory personnel are unfamiliar with the diagnosis and treatment of malaria.

OBJECTIVES

To examine the evidence base for management of uncomplicated and severe malaria and to provide clinicians with practical recommendations for the diagnosis and treatment of malaria in the United States.

EVIDENCE ACQUISITION

Systematic MEDLINE search from 1966 to 2006 using the search term malaria (with the subheadings congenital, diagnosis, drug therapy, epidemiology, and therapy). Additional references were obtained from searching the bibliographies of pertinent articles and by reviewing articles suggested by experts in the treatment of malaria in North America.

EVIDENCE SYNTHESIS

Important measures to reduce morbidity and mortality from malaria in the United States include the following: obtaining a travel history, considering malaria in the differential diagnosis of fever based on the travel history, and prompt and accurate diagnosis and treatment. Chloroquine remains the treatment of choice for Plasmodium falciparum acquired in areas without chloroquine-resistant strains. In areas with chloroquine resistance, a combination of atovaquone and proguanil or quinine plus tetracycline or doxycycline or clindamycin are the best treatment options. Chloroquine remains the treatment of choice for all other malaria species, with the exception of P vivax acquired in Indonesia or Papua New Guinea, in which case atovaquone-proguanil is best, with mefloquine or quinine plus tetracycline or doxycycline as alternatives. Quinidine is currently the recommended treatment for severe malaria in the United States because the artemisinins are not yet available. Severe malaria occurs when a patient with asexual malaria parasitemia, and no other confirmed cause of symptoms, has 1 or more designated clinical or laboratory findings. The only adjunctive measure recommended in severe malaria is exchange transfusion.

CONCLUSIONS

Malaria remains a diagnostic and treatment challenge for US clinicians as increasing numbers of persons travel to and emigrate from malarious areas. A strong evidence base exists to help clinicians rapidly initiate appropriate therapy and minimize the major mortality and morbidity burdens caused by this disease.

Atovaquone-proguanil: report from the CDC expert meeting on malaria chemoprophylaxis (II)

The fixed dose combination of atovaquone and proguanil hydrochloride, marketed under the trade name Malarone, is the most recently approved agent in North America for the prevention and treatment of chloroquine- and multi-drug resistant Plasmodium falciparum malaria. In both adult and pediatric populations, atovaquone-proguanil demonstrates consistently high protective efficacy against P. falciparum, and in treatment trials, cure rates exceed 93%. Only a handful of genetically confirmed treatment failures have been reported to date. Atovaquone-proguanil has an excellent safety profile during both prophylaxis and treatment courses, with severe adverse events rarely reported. This topical review will examine the evidence behind the current indications for use of atovaquone-proguanil, and will summarize the current body of literature surrounding safety and tolerability.

A randomized controlled trial of folate supplementation when treating malaria in pregnancy with sulfadoxine-pyrimethamine

OBJECTIVES

Sulfadoxine-pyrimethamine (SP) is an antimalarial drug that acts on the folate metabolism of the malaria parasite. We investigated whether folate (FA) supplementation in a high or a low dose affects the efficacy of SP for the treatment of uncomplicated malaria in pregnant women.

DESIGN

This was a randomized, placebo-controlled, double-blind trial.

SETTING

The trial was carried out at three hospitals in western Kenya.

PARTICIPANTS

The participants were 488 pregnant women presenting at their first antenatal visit with uncomplicated malaria parasitaemia (density of >or= 500 parasites/microl), a haemoglobin level higher than 7 g/dl, a gestational age between 17 and 34 weeks, and no history of antimalarial or FA use, or sulfa allergy. A total of 415 women completed the study.

INTERVENTIONS

All participants received SP and iron supplementation. They were randomized to the following arms: FA 5 mg, FA 0.4 mg, or FA placebo. After 14 days, all participants continued with FA 5 mg daily as per national guidelines. Participants were followed at days 2, 3, 7, 14, 21, and 28 or until treatment failure.

OUTCOME MEASURES

The outcomes were SP failure rate and change in haemoglobin at day 14.

RESULTS

The proportion of treatment failure at day 14 was 13.9% (19/137) in the placebo group, 14.5% (20/138) in the FA 0.4 mg arm (adjusted hazard ratio [AHR], 1.07; 98.7% confidence interval [CI], 0.48 to 2.37; p = 0.8), and 27.1% (38/140) in the FA 5 mg arm (AHR, 2.19; 98.7% CI, 1.09 to 4.40; p = 0.005). The haemoglobin levels at day 14 were not different relative to placebo (mean difference for FA 5 mg, 0.17 g/dl; 98.7% CI, -0.19 to 0.52; and for FA 0.4 mg, 0.14 g/dl; 98.7% CI, -0.21 to 0.49).

CONCLUSIONS

Concomitant use of 5 mg FA supplementation compromises the efficacy of SP for the treatment of uncomplicated malaria in pregnant women. Countries that use SP for treatment or prevention of malaria in pregnancy need to evaluate their antenatal policy on timing or dose of FA supplementation.

Primaquine: report from CDC expert meeting on malaria chemoprophylaxis I

Primaquine phosphate has been used for preventing relapse of Plasmodium vivax and P. ovale malaria since the early 1950s, based on its ability to kill latent (hypnozoite) and developing liver stages of these parasites. There are three uses for primaquine in malaria: radical cure of established infection with P. vivax or P. ovale malaria; presumptive anti-relapse therapy (PART; terminal prophylaxis) in persons with extensive exposure to these parasites; and primary prophylaxis against all malaria species. All persons for whom primaquine is being considered must have a glucose-6-phosphate dehydrogenase (G6PD) enzyme level checked before use, and persons who have a deficiency of G6PD must not take primaquine for prophylaxis or PART. The recommended adult dose for PART based on clinical trials and expert opinion is 30 mg base daily for 14 days, started on return from a malarious region and overlapping with a blood schizonticide. The adult dose for primary prophylaxis is 30 mg daily begun 1 day before travel and continued for 7 days after return. This review will examine the evidence for these recommendations.

Malaria prevention during pregnancy: assessing the disease burden one year after implementing a program of intermittent preventive treatment in Koupela District, Burkina Faso

The World Health Organization recommends that pregnant women in malaria-endemic areas receive >or= 2 doses of intermittent preventive treatment with sulfadoxine-pyrimethamine (IPTp/SP) in the second and third trimesters of pregnancy to prevent maternal anemia, placental parasitemia, and low birth weight (LBW). In 2001, a program evaluation in Koupéla District, Burkina Faso demonstrated that despite widespread use of chloroquine chemoprophylaxis, the burden of malaria during pregnancy remained high. In 2003, the Burkina Faso Ministry of Health piloted a program of IPTp/SP (three doses) and accelerated distribution of insecticide-treated nets (ITN) to pregnant women in Koupéla District. In 2004, a follow-up program evaluation was conducted. Coverage with >or= 1 doses of IPTp/SP was high among women attending antenatal clinics (ANCs) (96.2%) and delivery units (DUs) (93.5%); ITN ownership was moderately high (ANC = 53.9%, DU = 61.6%). In multivariate analysis, >or= 1 dose of IPTp/SP was associated with a significant reduction in the prevalence of peripheral parasitemia at ANCs (risk ratio [RR] = 0.49, P = 0.008), >or= 2 doses of IPTp/SP were associated with a reduction in the prevalence of placental parasitemia (RR = 0.56, P = 0.02), and three doses of IPTp/SP were associated with a reduced risk of LBW (RR = 0.51, P = 0.04). The proportions of women at ANCs with peripheral parasitemia and anemia were significantly lower in 2004 than in 2001 (RR = 0.53, P = 0.001 and RR = 0.78, P = 0.003, respectively). The proportions of women at DUs with peripheral and placental parasitemia were also significantly lower in 2004 than in 2001 (RR = 0.66, P < 0.0001 and RR = 0.71, P = 0.0002, respectively). These data suggest that a package of IPTp/SP and ITNs is effective in reducing the burden of malaria during pregnancy in Burkina Faso.

Randomized trial of 2-dose versus monthly sulfadoxine-pyrimethamine intermittent preventive treatment for malaria in HIV-positive and HIV-negative pregnant women in Malawi

BACKGROUND

Intermittent preventive treatment during pregnancy (IPTp) with sulfadoxine-pyrimethamine (SP) decreases placental malaria parasitemia and associated maternal anemia, premature delivery, and low birth weight. However, the optimal regimen in the setting of a high prevalence of human immunodeficiency virus (HIV) infection remains unclear.

METHODS

In Malawi, where the efficacy of SP for the treatment of malaria in children is decreasing, we conducted a randomized, nonblinded study to compare the efficacy of monthly SP IPTp with a 2-dose regimen for the prevention of placental parasitemia in HIV-positive and -negative primigravid and secundigravid women.

RESULTS

Of HIV-positive women, 7.8% who received monthly SP had placental malaria, compared with 21.5% of those who received 2-dose SP (relative risk [RR], 0.36 [95% confidence interval {CI}, 0.17-0.79]). Of HIV-negative women, 2.3% who received monthly SP and 6.3% who received 2-dose SP had placental malaria (RR, 0.37 [95% CI, 0.11-1.19]). Less than 1% of women reported adverse drug reactions, with no increase in HIV-positive women or those who received monthly SP.

CONCLUSIONS

In HIV-positive pregnant women, monthly SP IPTp is more efficacious than a 2-dose regimen in preventing placental malaria. The study also demonstrates the continued efficacy of SP for the prevention of placental malaria, even in the face of its decreasing efficacy for the treatment of malaria in children. In areas with intense transmission of falciparum malaria and a high prevalence of HIV infection, monthly SP IPTp should be adopted.

Malaria surveillance--United States, 2004

PROBLEM/CONDITION

Malaria in humans is caused by any of four species of intraerythrocytic protozoa of the genus Plasmodium (i.e., P. falciparum, P. vivax, P. ovale, or P. malariae). These parasites are transmitted by the bite of an infective female Anopheles sp. mosquito. The majority of malaria infections in the United States occur among persons who have traveled to areas with ongoing malaria transmission. In the United States, cases can occur through exposure to infected blood products, congenital transmission, or local mosquitoborne transmission. Malaria surveillance is conducted to identify episodes of local transmission and to guide prevention recommendations for travelers.

PERIOD COVERED

This report summarizes cases in persons with onset of illness in 2004 and summarizes trends during previous years.

DESCRIPTION OF SYSTEM

Malaria cases confirmed by blood film are mandated to be reported to local and state health departments by health-care providers or laboratory staff. Case investigations are conducted by local and state health departments, and reports are transmitted to CDC through the National Malaria Surveillance System (NMSS). Data from NMSS serve as the basis for this report.

RESULTS

CDC received reports of 1,324 cases of malaria, including four fatal cases, with an onset of symptoms in 2004 among persons in the United States or one of its territories. This number represents an increase of 3.6% from the 1,278 cases reported for 2003. P. falciparum, P. vivax, P. malariae, and P. ovale were identified in 49.6%, 23.8%, 3.6%, and 2.0% of cases, respectively. Seventeen patients (1.3% of total) were infected by two or more species. The infecting species was unreported or undetermined in 262 (19.8%) cases. Compared with 2003, the number of reported malaria cases acquired in the Americas (n = 173) increased 17.7%, whereas the number of cases acquired in Asia (n = 172) and Africa (n = 809) decreased 2.8% and 3.7%, respectively. Of 775 U.S. civilians who acquired malaria abroad, only 160 (20.6%) reported that they had followed a chemoprophylactic drug regimen recommended by CDC for the area to which they had traveled. Four patients became infected in the United States; three cases were attributed to congenital transmission and one to laboratory-related mosquitoborne transmission. Four deaths were attributed to malaria, including two caused by P. falciparum, one by P. vivax, and one by a mixed infection with P. falciparum and P. malariae.

INTERPRETATION

The 3.6% increase in malaria cases in 2004, compared with 2003, resulted primarily from an increase in the number of cases acquired in the Americas but was offset by a decrease in the number of cases acquired in Africa and Asia. This limited increase might reflect local changes in disease transmission, increased travel to regions in which malaria is endemic, or fluctuations in reporting to state and local health departments. These changes likely reflect expected variation in annual reporting and should not be interpreted as indicating a longer-term trend. In the majority of reported cases, U.S. civilians who acquired infection abroad had not adhered to a chemoprophylaxis regimen that was appropriate for the country in which they acquired malaria.

PUBLIC HEALTH ACTIONS

Additional investigations were conducted for the four fatal cases and four infections acquired in the United States. Persons traveling to a malarious area should take one of the recommended chemoprophylaxis regimens appropriate for the region of travel and use personal protection measures to prevent mosquito bites. Any person who has been to a malarious area and who subsequently has a fever or influenza-like symptoms should seek medical care immediately and report their travel history to the clinician; investigation should include a blood-film test for malaria. Malaria infections can be fatal if not diagnosed and treated promptly. Recommendations concerning malaria prevention can be obtained from CDC at http://www.cdc.gov/travel or by calling the Malaria Hotline at telephone 770-488-7788. Recommendations concerning malaria treatment can be obtained at http://www.cdc.gov/malaria/diagnosis_treatment/treatment.htm or by calling the Malaria Hotline.

Prevention of malaria during pregnancy in West Africa: policy change and the power of subregional action

BACKGROUND

Despite a broadening consensus about the effectiveness of intermittent preventive treatment (IPTp) in preventing the adverse outcomes of malaria during pregnancy, policy change to IPTp was initially limited to East Africa. In West Africa, where the policy change process for the prevention of malaria during pregnancy started much later, IPTp has been taken up swiftly.

OBJECTIVE

To describe the factors that contributed to the rapid adoption of policies to prevent malaria during pregnancy in West Africa.

RESULTS AND CONCLUSION

Several factors appear to have accelerated the process: (1) recognition of the extent of the problem of malaria during pregnancy and its adverse consequences; (2) a clear, evidence-based program strategy strongly articulated by an important multilateral organization (World Health Organization); (3) subregionally generated evidence to support the proposed strategy; (4) a subregional forum for dissemination of data and discussion regarding the proposed policy changes; (5) widespread availability of the proposed intervention drug (sulfadoxine-pyrimethamine); (6) technical support from reputable and respected institutions in drafting new policies and planning for implementation; (7) donor support for pilot experiences in integrating proposed policy change into a package of preventive services; and (8) financial support for scaling up the proposed interventions.

Malaria surveillance--United States, 2003

PROBLEM/CONDITION

Malaria in humans is caused by any of four species of intraerythrocytic protozoa of the genus Plasmodium (i.e., P. falciparum, P. vivax, P. ovale, or P. malariae). These parasites are transmitted by the bite of an infective female Anopheles sp. mosquito. The majority of malaria infections in the United States occur among persons who have traveled to areas with ongoing transmission. In the United States, cases can also occur through exposure to infected blood products, by congenital transmission, or by local mosquitoborne transmission. Malaria surveillance is conducted to identify episodes of local transmission and to guide prevention recommendations for travelers.

PERIOD COVERED

This report covers cases with onset of illness in 2003, and summarizes trends over previous years.

DESCRIPTION OF SYSTEM

Malaria cases confirmed by blood film are mandated to be reported to local and state health departments by health-care providers or laboratory staff. Case investigations are conducted by local and state health departments, and reports are transmitted to CDC through the National Malaria Surveillance System (NMSS). Data from NMSS serve as the basis for this report.

RESULTS

CDC received reports of 1,278 cases of malaria with an onset of symptoms in 2003, including seven fatal cases, among persons in the United States or one of its territories. This number represents a decrease of 4.4% from the 1,337 cases reported for 2002. P. falciparum, P. vivax, P. malariae, and P. ovale were identified in 53.3%, 22.9%, 3.6%, and 2.6% of cases, respectively. Twelve patients (0.9% of total) were infected by two or more species. The infecting species was unreported or undetermined in 212 (16.6%) cases. Compared with 2002, the number of reported malaria cases acquired in Asia (n = 177) and the Americas (n = 147) increased by 3.5% and 4.3% respectively, whereas the number of cases acquired in Africa (n = 840) decreased by 7.0%. Of 762 U.S. civilians who acquired malaria abroad, 132 (17.3%) reported that they had followed a chemoprophylactic drug regimen recommended by CDC for the area to which they had traveled. Ten patients became infected in the United States, including one probable transfusion-related, one in which epidemiologic investigations failed to identify any apparent mode of acquisition, and eight which were introduced cases as a result of local mosquitoborne transmission. Of the seven deaths attributed to malaria, five were caused by P. falciparum, and a species was not identified in the other two.

INTERPRETATION

The 4.4% decrease in malaria cases in 2003, compared with 2002, resulted primarily from a decrease in cases acquired in Africa, but this decrease was offset by an increase in the number of cases acquired in the Americas and Asia. This small decrease probably represents year-to-year variation in malaria cases, but also could have resulted from local changes in disease transmission, decreased travel to malaria-endemic regions, or fluctuation in reporting to state and local health departments. In the majority of reported cases, U.S. civilians who acquired infection abroad were not on an appropriate chemoprophylaxis regimen for the country in which they acquired malaria.

PUBLIC HEALTH ACTION

Additional information was obtained concerning the seven fatal cases and the 10 infections acquired in the United States. Persons traveling to a malarious area should take one of the recommended chemoprophylaxis regimens appropriate for the region of travel, and travelers should use personal protection measures to prevent mosquito bites. Any person who has been to a malarious area and who subsequently experiences a fever or influenza-like symptoms should seek medical care immediately and report their travel history to the clinician; investigation should include a blood-film test for malaria. Malaria infections can be fatal if not diagnosed and treated promptly. Recommendations concerning malaria prevention can be obtained from CDC by calling the Malaria Hotline at 770-488-7788 or by accessing CDC's Internet site at http://www.cdc.gov/travel. Recommendations concerning diagnosis of malaria and its treatment can be obtained by calling the Malaria Hotline or accessing CDC's Internet site at http://www.cdc.gov/malaria/diagnosis_treatment/treatment.htm.

Comparison of Intermittent Preventive Treatment with Chemoprophylaxis for the Prevention of Malaria during Pregnancy in Mali

BACKGROUND

Malaria during pregnancy contributes to maternal anemia and low birth weight. In East Africa, several studies have demonstrated that intermittent preventive treatment (IPT) with sulfadoxine-pyrimethamine (SP) is more efficacious than weekly chloroquine (CQ) chemoprophylaxis in preventing these adverse consequences. To our knowledge, there are no published trials evaluating IPT in West Africa.

METHODS

We undertook a randomized controlled trial of weekly CQ chemoprophylaxis, 2-dose IPT with CQ, and 2-dose IPT with SP; 1163 women were enrolled.

RESULTS

In multivariate analyses, when compared with weekly CQ, IPT/SP was associated with a reduction in third-trimester anemia (adjusted odds ratio [AOR], 0.49; P<.001), placental parasitemia (AOR, 0.69; P=.04), and low birth weight (<2500 g) (AOR, 0.69; P=.04). The prevalence of placental infection remained unexpectedly high, even in the IPT/SP group (24.5%), possibly because of the intensity of seasonal transmission. There were no significant differences in stillbirths, spontaneous abortions, or neonatal deaths among the 3 groups.

CONCLUSIONS

In Mali, IPT with SP appears more efficacious than weekly chloroquine chemoprophylaxis in preventing malaria during pregnancy. These data support World Health Organization recommendations to administer at least 2 doses of IPT during pregnancy. In intensely seasonal transmission settings in Mali, >2 doses may be required to prevent placental reinfection prior to delivery.

Care seeking behaviour and treatment of febrile illness in children aged less than five years: a household survey in Blantyre District, Malawi

Malaria is a leading cause of death in children aged < 5 years in Malawi. As part of the Roll Back Malaria initiative, African heads of state have pledged that by 2005, 60% of children will receive an effective antimalarial drug within 24 h of developing fever. In 1993, Malawi switched from chloroquine to sulfadoxine-pyrimethamine (SP) in its recommendations of home treatment of febrile illness in children. To study care seeking behaviour and home treatment in Blantyre District, and provide valuable follow-up to the chloroquine to SP transition, we performed a 2-stage cluster-sample survey in February 2000. Our sample of 1080 households included 672 households with children aged < 5 years; 292 (32.2%, 95% CI 28.7-35.8%) of the 912 children in these households had completed a febrile episode within the past 14 d. Among recently febrile children, 210 (72.0%, 95% CI 67.0-77.1%) received medication at home during their illness, but only 36 (12.2%, 95% CI 8.4-16.0%) received an appropriate antimalarial drug. Overall, 111 (37.4%, 95% CI 30.9-43.9%) received prompt, appropriate treatment. Only rural location was statistically associated with failure to receive prompt appropriate treatment (risk ratio estimate 1.2, 95% CI 1.01-1.5). A greater effort to improve the quality of malaria home treatment or to expand health facility utilization will be necessary to achieve Roll Back Malaria goals before 2005 in Blantyre District. Current care seeking practices suggest interventions should stress promptness of health facility visits, improved access to appropriate drugs, and accurate dosing for home-based treatments.

Malaria-related deaths among U.S. travelers, 1963-2001

Nearly 1500 malaria cases occur each year in the United States; approximately 60% are among U.S. travelers. Despite the availability of sophisticated medical care, malaria-related deaths continue to occur. The authors reviewed all 185 fatal cases between 1963 and 2001 that were reported to the National Malaria Surveillance System: 123 (66.5%) occurred among U.S. travelers, and of these, 114 (92.7%) were attributed to Plasmodium falciparum. Failure to take or adhere to recommended chemoprophylaxis, to promptly seek medical care for post-travel illness, and to promptly diagnose and treat suspected malaria all contributed to fatal outcomes. Health care providers need to take a travel history, obtain a blood film for suspected malaria, and use the 24-hour malaria management advice available through the Centers for Disease Control and Prevention (CDC) Malaria Hotline (770-488-7788) or the CDC Malaria Web site (http://www.cdc.gov/Malaria). Hospitals must maintain intravenous quinidine gluconate on formulary because it is the only drug available to treat severe malaria in the United States.

The burden of co-infection with human immunodeficiency virus type 1 and malaria in pregnant women in sub-saharan Africa

In sub-Saharan Africa, human immunodeficiency virus (HIV) and malaria are among the leading causes of morbidity during pregnancy. We reviewed available information collected since the first report 15 years ago that HIV impaired the ability of pregnant women to control malaria parasitemia. Results from 11 studies showed that HIV-infected women experienced consistently more peripheral and placental malaria (summary relative risk = 1.58 and 1.66, respectively), higher parasite densities, and more febrile illnesses, severe anemia, and adverse birth outcomes than HIV-uninfected women, particularly in multigravidae. Thus, HIV alters the typical gravidity-specific pattern of malaria risk by shifting the burden from primarily primigravidae and secundigravidae to all pregnant women. The proportional increase of malaria during pregnancy attributable to HIV was estimated to be 5.5% and 18.8% for populations with HIV prevalences of 10% and 40%, respectively. Maternal malaria was associated with a two-fold higher HIV-1 viral concentrations. Three studies investigating whether placental malaria increased mother-to-child HIV-1 transmission showed conflicting results, possibly reflecting a complex balance between placental malarial immune responses and stimulation of HIV-1 viral replication. Further investigations of interactions between antiretroviral drugs, prophylaxis with cotrimoxazole, and antimalarial drugs in pregnant women are urgently needed. Although much has been learned in the past 15 years about the interaction between malaria and HIV-1 during pregnancy, many issues still require further information to improve our understanding. There is a clear need to strengthen the deployment of existing malaria and HIV prevention and intervention measures for pregnant women.

Evaluation of a malaria rapid diagnostic test for assessing the burden of malaria during pregnancy

Plasmodium falciparum infection during pregnancy may cause placental malaria and subsequently low birth weight, primarily through the placental sequestration of infected red blood cells. Measuring the burden of malaria during pregnancy usually involves determining the prevalence of placental malaria infection through microscopic examination of placental blood films, a difficult and error-prone process. A number of rapid diagnostic tests (RDTs) for malaria have been developed, most of them immunochromatographic dipstick assays. However, none have been tested for the direct determination of malaria antigen in placental blood. We undertook an evaluation of the Malaria Rapid Test (MAKROmed in determining placental malaria infection. The prevalence of placental parasitemia was 22.6% by microscopy, 51.0% by a polymerase chain reaction (PCR), and 43.1% by RDT. When the PCR was used as the gold standard, RDTs had a sensitivity of 89% and a specificity of 76%. The MAKROmed RDT was highly sensitive in the detection of placental malaria, but had lower than expected specificity.

Malaria surveillance--United States, 2002

PROBLEM/CONDITION

Malaria is caused by any of four species of intraerythrocytic protozoa of the genus Plasmodium (i.e., P. falciparum, P. vivax, P. ovale, or P. malariae). These parasites are transmitted by the bite of an infective female Anopheles species mosquito. The majority of malaria infections in the United States occur among persons who have traveled to areas with ongoing transmission. In the United States, cases can occur through exposure to infected blood products, by congenital transmission, or by local mosquitoborne transmission. Malaria surveillance is conducted to identify episodes of local transmission and to guide prevention recommendations for travelers.

PERIOD COVERED

This report covers cases with onset of illness in 2002.

DESCRIPTION OF SYSTEM

Malaria cases confirmed by blood film are reported to local and state health departments by health-care providers or laboratory staff. Case investigations are conducted by local and state health departments, and reports are transmitted to CDC through the National Malaria Surveillance System (NMSS). Data from NMSS serve as the basis for this report.

RESULTS

CDC received reports of 1,337 cases of malaria with an onset of symptoms in 2002 among persons in the United States or one of its territories. This number represents a decrease of 3.3% from the 1,383 cases reported for 2001. P. falciparum, P. vivax, P. malariae, and P. ovale were identified in 52.3%, 25.4%, 2.8%, and 2.8% of cases, respectively. Eleven patients (0.8% of total) were infected by > or =2 species. The infecting species was unreported or undetermined in 213 (15.9%) cases. Compared with 2001, the number of reported malaria cases acquired in Asia (n = 171) and Africa (n = 903) increased by 4.3% and 1.9%, respectively, whereas the number of cases acquired in the Americas (n = 141) decreased by 41.2%. Of 849 U.S. civilians who acquired malaria abroad, 317 (37.3%) reported that they had followed a chemoprophylactic drug regimen recommended by CDC for the area to which they had traveled. Five patients became infected in the United States, one through congenital transmission, one probable transfusion-related, and three whose infection cannot be linked epidemiologically to secondary cases. Eight deaths were attributed to malaria. All deaths were caused by P. falciparum.

INTERPRETATION

The 3.3% decrease in malaria cases in 2002, compared with 2001, resulted primarily from a marked decrease in cases acquired in the Americas, but this decrease was offset somewhat by an increase in the number of cases acquired in Africa and Asia. This limited decrease probably represents year-to-year variation in malaria cases, but also could have resulted from local changes in disease transmission, decreased travel to malaria-endemic regions, fluctuation in reporting to state and local health departments, or an increased use of effective antimalarial chemoprophylaxis. In the majority of reported cases, U.S. civilians who acquired infection abroad were not on an appropriate chemoprophylaxis regimen for the country in which they acquired malaria.

PUBLIC HEALTH ACTION

Additional information was obtained concerning the eight fatal cases and the five infections acquired in the United States. Persons traveling to a malarious area should take one of the recommended chemoprophylaxis regimens appropriate for the region of travel, and travelers should use personal protection measures to prevent mosquito bites. Any person who has been to a malarious area and who subsequently experiences a fever or influenza-like symptoms should seek medical care immediately and report their travel history to the clinician; investigation should include a blood-film test for malaria. Malaria infections can be fatal if not diagnosed and treated promptly. Recommendations concerning malaria prevention can be obtained from CDC by calling the Malaria Hotline at 770-488-7788 or by accessing CDC's Internet site at http://www.cdc.gov/travel.

Use of antenatal care services and intermittent preventive treatment for malaria among pregnant women in Blantyre District, Malawi

Malaria in pregnancy contributes to low birth weight and increased infant mortality. As part of WHO's Roll Back Malaria initiative, African heads of state pledged that by 2005, 60% of pregnant women will receive malaria chemoprophylaxis or intermittent preventive treatment (IPT). We performed a cluster sample survey to study the use of sulfadoxine-pyrimethamine (SP) for IPT among recently pregnant women in February 2000 in Blantyre District, Malawi. Among 391 women in the sample, 98.6% had attended antenatal clinic at least once and 90.2% knew that SP/IPT was recommended during pregnancy. Overall, only 36.8% received the full recommended two-dose regimen of SP/IPT. Using data from 187 women with antenatal clinic cards, we found that residence location, housing type and gender/age/education of the head of household were not associated with failure to receive SP/IPT. Adjusting for education, multigravid women were more likely not to receive the recommended SP/IPT regimen (RR 1.2, 95% CI 1.02-1.5, P=0.03). A substantial effort to improve the delivery and use of SP/IPT in Malawi will be necessary, but the Roll Back Malaria 2005 goal appears achievable.

Plasmodium vivax malaria in spite of atovaquone/proguanil (malarone) prophylaxis

A 70-year-old male scientist, who had returned 5 weeks earlier from Ethiopia, was admitted to the hospital with symptoms consistent with malaria. On physical examination, he had orthostatic hypotension. He was dehydrated and showed a mild clinical delirium. Abdominal examination revealed a possible spleen tip, and he had petechial lesions bilaterally below his knees. Laboratory data revealed his white blood cell count to be 4,500/mL, with 67% polymorphonuclear cells and 15% band forms. The hemoglobin level was 13.9 g/dL, and the platelet count was low, at 32,000/mL.

Malaria surveillance--United States, 2001

PROBLEM/CONDITION

Malaria is caused by any of four species of intraerythrocytic protozoa of the genus Plasmodium (i.e., P. falciparum, P. vivax, P. ovale, or P. malariae). These parasites are transmitted by the bite of an infective female Anopheles sp. mosquito. The majority of malaria infections in the United States occur among persons who have traveled to areas with ongoing transmission. In the United States, cases can occur through exposure to infected blood products, by congenital transmission, or by local mosquitoborne transmission. Malaria surveillance is conducted to identify episodes of local transmission and to guide prevention recommendations for travelers.

PERIOD COVERED

This report covers cases with onset of illness in 2001.

DESCRIPTION OF SYSTEM

Malaria cases confirmed by blood film are reported to local and state health departments by health-care providers or laboratory staff. Case investigations are conducted by local and state health departments, and reports are transmitted to CDC through the National Malaria Surveillance System (NMSS). Data from NMSS serve as the basis for this report.

RESULTS

CDC received reports of 1,383 cases of malaria with an onset of symptoms in 2001 among persons in the United States or one of its territories. This number represents a decrease of 1.4% from the 1,402 cases reported for 2000. P. falciparum, P. vivax, P. malariae, and P. ovale were identified in 50.1%, 27.8%, 4.5%, and 3.6% of cases, respectively. Fourteen patients (1.0% of total) were infected by >/=2 species. The infecting species was unreported or undetermined in 179 (12.9%) cases. Compared with 2000, the number of reported malaria cases acquired in Africa increased by 13.2% (n = 886), whereas the number of cases acquired in Asia (n = 163) and the Americas (n = 240) decreased by 31.5% and 11.4%, respectively. Of 891 U.S. civilians who acquired malaria abroad, 180 (20.2%) reported that they had followed a chemoprophylactic drug regimen recommended by CDC for the area to which they had traveled. Two patients became infected in the United States, one through congenital transmission and one whose infection cannot be linked epidemiologically to secondary cases. Eleven deaths were attributed to malaria, 10 caused by P. falciparum and one caused by P. ovale.

INTERPRETATION

The 1.4% decrease in malaria cases in 2001, compared with 2000, resulted primarily from a decrease in cases acquired in Asia and the Americas, but this decrease was offset by an increase in the number of cases acquired in Africa. This decrease probably represents year-to-year variation in malaria cases, but also could have resulted from local changes in disease transmission, decreased travel to malaria-endemic regions, fluctuation in reporting to state and local health departments, or an increased use of effective antimalarial chemoprophylaxis. In the majority of reported cases, U.S. civilians who acquired infection abroad were not on an appropriate chemoprophylaxis regimen for the country in which they acquired malaria.

PUBLIC HEALTH ACTIONS

Additional information was obtained concerning the 11 fatal cases and the two infections acquired in the United States. Persons traveling to a malarious area should take one of the recommended chemoprophylaxis regimens appropriate for the region of travel, and travelers should use personal protection measures to prevent mosquito bites. Any person who has been to a malarious area and who subsequently develops a fever or influenza-like symptoms should seek medical care immediately and report their travel history to the clinician; investigation should include a blood-film test for malaria. Malaria infections can be fatal if not diagnosed and treated promptly. Recommendations concerning malaria prevention can be obtained from CDC by calling the Malaria Hotline at 770-488-7788 or by accessing CDC's Internet site at http://www.cdc.gov/travel.

Safety, efficacy and determinants of effectiveness of antimalarial drugs during pregnancy: implications for prevention programmes in Plasmodium falciparum-endemic sub-Saharan Africa

Plasmodium falciparum malaria in pregnancy poses substantial risk to a pregnant woman and her neonate through anaemia and low birth weight (LBW), respectively, and is responsible for up to 35% of preventable LBW in malaria-endemic areas. Chemoprophylaxis or intermittent preventive treatment (IPT) with an effective antimalarial can ameliorate the adverse effects of malaria during pregnancy. Current guidelines from the WHO recommend that women in highly malarious areas receive IPT with an effective antimalarial. Two central considerations in evaluating drugs for use during pregnancy are safety for the mother and her foetus and effectiveness, which is determined by efficacy, cost, availability, deliverability and acceptability of the drug. These factors may be scored and potential drugs or drug combinations ranked in order of potential effectiveness for use in prevention programmes. The seven most promising regimens are all IPT, primarily because they are more easily delivered and less expensive than chemoprophylaxis. Currently, IPT with sulphadoxine-pyrimethamine (SP) is more likely to have the best overall effectiveness in preventing adverse outcomes associated with malaria in pregnancy. Its low cost, wide availability, easy deliverability and acceptability make it the clear choice in countries where efficacy of the drug remains good. For countries where resistance to SP is rising or already high, amodiaquine (alone or in combination with SP or artesunate) artesunate + SP, chlorproguanil-dapsone (with and without artesunate) and artemether-lumefantrine require urgent evaluation for use in pregnancy.

Burden of malaria during pregnancy in areas of stable and unstable transmission in Ethiopia during a nonepidemic year

Little is known about the epidemiology of malaria during pregnancy in areas of unstable (epidemic-prone) transmission (UT) in sub-Saharan Africa. In cross-sectional studies, peripheral malaria parasitemia was identified in 10.4% of women attending antenatal care clinics at 1 stable transmission (ST) site and in 1.8% of women at 3 UT sites; parasitemia was associated with anemia in both ST (relative risk [RR], 2.0; P<.001) and UT (RR, 4.4; P<.001) sites. Placental parasitemia was identified more frequently during deliveries at ST sites (12/185; 6.5%) than at UT sites (21/833; 2.5%; P=.006). Placental parasitemia was associated with low birth weight at the ST site (RR, 3.2; P=.01) and prematurity at ST (RR, 2.7; P=.04) and UT (RR, 3.9; P=.01) sites and with a 7-fold increased risk of stillbirths at UT sites. The effectiveness and efficiency in Ethiopia of standard preventive strategies used in high-transmission regions (such as intermittent preventive treatment) may require further evaluation; approaches such as insecticide-treated bednets and epidemic preparedness may be needed to prevent adverse pregnancy outcomes.

Failure of a chloroquine chemoprophylaxis program to adequately prevent malaria during pregnancy in Koupéla District, Burkina Faso

In West Africa, administration of chloroquine chemoprophylaxis during pregnancy is common, but little is known about its impact on Plasmodium falciparum infection during pregnancy. Therefore, cross-sectional studies in antenatal care clinics (ANCs) and delivery units (DUs) were conducted in Koupéla District, Burkina Faso. Chloroquine chemoprophylaxis was reported by 69% of 597 pregnant women at ANCs and by 93% of 853 women in DUs. P. falciparum peripheral parasitemia was identified in 29% of women at both ANCs and DUs. Placental parasitemia was identified in 22% of delivering women and was strongly associated with low birth weight (LBW) (risk ratio [RR], 1.7; 95% confidence interval [CI], 1.2-2.4) and prematurity (RR, 2.9; 95% CI, 1.6-5.4). In multivariate analysis, use of chemoprophylaxis was not associated with a reduction in the prevalence of placental parasitemia, LBW, or prematurity. Despite the high reported chloroquine chemoprophylaxis coverage, peripheral and placental malaria rates remain high and are associated with known adverse outcomes during pregnancy, including maternal anemia, prematurity, and LBW. Alternative prevention strategies, such as use of insecticide-treated mosquito nets and intermittent preventive treatment with more-effective antimalarials, are needed.

A rapid assessment approach for public health decision-making related to the prevention of malaria during pregnancy

OBJECTIVE

To develop a rapid field assessment methodology to address the burden of malaria during pregnancy and the options for intervening within the existing antenatal care system in Kenya.

METHODS

Surveys consisting of questionnaires, sampling of blood for parasitaemia and anaemia, and birth outcome assessment were conducted in antenatal clinics, delivery units, and in the community in Kisumu and Mombasa, Kenya.

FINDINGS

The rates of maternal anaemia and severe anaemia, were, respectively, 79% and 8% in Kisumu, and 95% and 24% in Mombasa. The rates of placental parasitaemia were 27% and 24% and the rates of low birth weight were 18% and 24% in Kisumu and Mombasa, respectively. Women with placental parasitaemia had a higher incidence of low birth weight compared with women without placental parasitaemia in both Kisumu (28% vs 16%, P=0.004) and Mombasa (42% vs 20%, P=0.004). A total of 95% and 98% of women in Kisumu and Mombasa, respectively, reported attending an antenatal clinic during their previous pregnancy.

CONCLUSION

This methodology can be used by ministries of health to collect data for decision-making regarding malaria control during pregnancy; it can also provide a baseline measurement on which to evaluate subsequent interventions.

Malaria surveillance--United States, 1999

PROBLEM/CONDITION

Malaria is caused by four species of intraerythrocytic protozoa of the genus Plasmodium (i.e., P. falciparum, P. vivax, P. ovale, or P. malariae). Malaria is transmitted by the bite of an infective female Anopheles sp. mosquito. The majority of malaria infections in the United States occur in persons who have traveled to areas with ongoing transmission. In the United States, cases can occur through exposure to infected blood products, by congenital transmission, or locally through mosquitoborne transmission. Malaria surveillance is conducted to identify episodes of local transmission and to guide prevention recommendations for travelers.

PERIOD COVERED

Cases with onset of illness during 1999.

DESCRIPTION OF SYSTEM

Malaria cases confirmed by blood films are reported to local and state health departments by health-care providers or laboratory staff. Case investigations are conducted by local and state health departments, and reports are transmitted to CDC through the National Malaria Surveillance System (NMSS). Data from NMSS serve as the basis for this report.

RESULTS

CDC received reports of 1,540 cases of malaria with an onset of symptoms during 1999 among persons in the United States or one of its territories. This number represents an increase of 25.5% from the 1,227 cases reported for 1998. P. falciparum, P. vivax, P. malariae, and P. ovale were identified in 46.0%, 30.7%, 4.6%, and 3.6% of cases, respectively. More than one species was present in 12 patients (0.8% of total). The infecting species was unreported or undetermined in 223 (14.5%) cases. The number of reported malaria cases acquired in Africa increased 27.6% (n = 901), compared with 1998, and an increase of 2.9% (n = 246) occurred in cases acquired in Asia, compared with 1998. Cases from the Americas increased by 19.7% (n = 274) from 1998. Of 831 U.S. civilians who acquired malaria abroad, 159 (19.1%) reported that they had followed a chemoprophylactic drug regimen recommended by CDC for the area to which they had traveled. Three patients became infected in the United States, all through probable local mosquitoborne transmission. Five deaths were attributed to malaria, all caused by P. falciparum.

INTERPRETATION

The 25.5% increase in malaria cases in 1999, compared with 1998, resulted primarily from increases in cases acquired in Africa and the Americas. This increase is possibly related to a change in the system by which states report to CDC, but it could also have resulted from local changes in disease transmission, increased travel to these regions, improved reporting to state and local health departments, or a decreased use of effective antimalarial chemoprophylaxis. In the majority of reported cases, U.S. civilians who acquired infection abroad were not on an appropriate chemoprophylaxis regimen for the country where they acquired malaria.

PUBLIC HEALTH ACTIONS

Additional information was obtained concerning the five fatal cases and the three infections acquired in the United States. The NMSS surveillance form was modified to gather more detailed information regarding compliance with prescribed chemoprophylaxis regimens. Persons traveling to a malarious area should take one of the recommended chemoprophylaxis regimens appropriate to the region of travel, and travelers should use personal protection measures to prevent mosquito bites. Any person who has been to a malarious area and who subsequently develops a fever or influenza-like symptoms should seek medical care immediately; investigation should include a blood-film test for malaria. Malaria infections can be fatal if not diagnosed and treated promptly. Recommendations concerning prevention of malaria can be obtained from CDC.

Insecticide-treated bednet use, anaemia, and malaria parasitaemia in Blantyre District, Malawi

OBJECTIVE

To evaluate the use of insecticide-treated bednets and the effectiveness of social marketing for their distribution.

METHODS

Systematic cluster sample survey of 1080 households in 36 census enumeration areas across Blantyre district, Malawi, in February 2000.

RESULTS

A total of 672 households had one or more children under 5. Bednet ownership was low (20.5% of households) overall, and significantly lower in rural areas than urban areas (6.4 vs. 29.8%, P=0.001). Only 3.3% of rural children under 5 had slept under a net the previous night, compared with 24.0% of urban children (P < 0.001). When asked why they did not own a net, nearly all (94.9%) caretakers in households without nets stated they had no money to buy them. In multivariate statistical models that controlled for the influence of house structure, urban vs. rural location, gender of the head of household, and the primary caretaker's education, rural children under 5 in households without nets experienced a statistically significant higher prevalence of malaria parasitaemia [RR (risk ratio) 4.9, 95% CI (confidence interval) 2.3-10.5] than children in households with at least one bednet. This was also true for urban children under 5 (RR 2.1, 95% CI 1.0-4.2, P=0.04).

CONCLUSION

Social marketing approaches to promoting insecticide-treated nets in Blantyre District may have produced measurable health benefits for children in those households in which residents bought and used the products. Market-based approaches may take years to achieve high levels of coverage and may exaggerate inequities between urban and rural populations.

Malaria surveillance--United States, 1998

PROBLEM/CONDITION

Human malaria is caused by one or more of four species of intraerythrocytic protozoa of the genus Plasmodium (i.e., P. falciparum, P. vivax, P. ovale, or P. malariae). The protozoa are transmitted by the bite of an infective female Anopheles species mosquito. The majority of malaria infections in the United States occur among persons who have traveled to areas with endemic transmission. Cases occasionally occur that are acquired through exposure to infected blood products, by congenital transmission, or by local mosquitoborne transmission. Malaria surveillance is conducted to identify episodes of local transmission and to guide prevention recommendations for travelers.

REPORTING PERIOD

Cases with an onset of symptoms during 1998.

DESCRIPTION OF SYSTEM

Malaria cases confirmed by blood smear are reported to local and state health departments by health-care providers and laboratory staff members. Case investigations are conducted by local and state health departments, and reports are sent to CDC through the National Malaria Surveillance System (NMSS). This report uses NMSS data.

RESULTS

CDC received reports of 1,227 cases of malaria with onsets of symptoms in 1998, among persons in the United States and its territories. This number represents a decrease of 20.5% from the 1,544 cases reported during 1997. P. falciparum, P. vivax, P. malariae, and P. ovale were identified in 42.8%, 37.8%, 3.5%, and 2.1% of cases, respectively. More than one species was present in seven patients (0.6% of total). The infecting species was not determined in 162 (13.2%) cases. Compared with reported cases in 1997, reported malaria cases acquired in Africa increased by 1.3% (n = 706); those acquired in Asia decreased by 52.1% (n = 239); and those acquired in the Americas decreased by 6.5% (n = 229). Of 636 U.S. civilians who acquired malaria abroad, 126 (19.8%) reportedly had followed a chemoprophylactic drug regimen recommended by CDC for the area to which they had traveled. Five persons became infected in the United States. One case was congenitally acquired; one was acquired by blood transfusion; and three were isolated cases that could not be epidemiologically linked to another case. Four deaths were attributed to malaria.

INTERPRETATION

The 20.5% decrease in malaria cases during 1998 compared with 1997 resulted primarily from decreases in P. vivax cases acquired in Asia among non-U.S. civilians. This decrease could have resulted from local changes in disease transmission, decreased immigration from the region, decreased travel to the region, incomplete reporting from state and local health departments, or increased use of effective antimalarial chemoprophylaxis. In a majority of reported cases, U.S. civilians who acquired infection abroad had not taken an appropriate chemoprophylaxis regimen for the country where they acquired malaria. PUBLIC HEALTH ACTIONS TAKEN: Additional information was obtained from state and local health departments and clinics concerning the four fatal cases and the five infections acquired in the United States. Persons traveling to a malarious area should take a recommended chemoprophylaxis regimen and use personal protection measures to prevent mosquito bites. Any person who has been to a malarious area and subsequently develops fever or influenza-like symptoms should seek medical care immediately; the investigation should include a blood smear for malaria. Malaria infections can be fatal if not diagnosed and treated promptly. Current recommendations concerning prevention and treatment of malaria can be obtained from CDC.

Probable locally acquired mosquito-transmitted malaria in Georgia, 1999

In July 1999, the Centers for Disease Control and Prevention received notification of a case of malaria in a 32-year-old female native of Colquitt County, Georgia, who had no history of travel into an area where malaria transmission is endemic. An epidemiological investigation confirmed the absence of risk factors, such as blood transfusion, organ transplantation, malariotherapy, needle sharing, or past malaria infection. Active case finding revealed no other infected persons in Colquitt County. Light trapping and larvae-dipping failed to identify adult or larval anophelines; however, Colquitt County is known to be inhabited by Anopheles quadrimaculatus, a competent malaria vector. The patient's home was located near housing used by seasonal migrant workers from regions of southern Mexico and Central America where malaria is endemic, one of whom may have been the infection source. The occurrence of malaria in this patient with no risk factors, except for proximity to potentially gametocytemic hosts, suggests that this illness probably was acquired through the bite of an Anopheles species mosquito.

Cost-effectiveness of sulfadoxine-pyrimethamine for the prevention of malaria-associated low birth weight

Prevention of placental malaria through administration of antimalarial medications to pregnant women in disease-endemic areas decreases the risk of delivery of low birth weight (LBW) infants. In areas of high Plasmodium falciparum transmission, two intermittent presumptive treatment doses of sulfadoxine-pyrimethamine (SP) during the second and third trimesters of pregnancy are effective in decreasing the prevalence of placental malaria in human immunodeficiency virus (HlV)-negative women, while HIV-positive women may require a monthly SP regimen to reduce their prevalence of placental parasitemia. A decision-analysis model was used to compare the cost-effectiveness of three different presumptive SP treatment regimens with febrile case management with SP in terms of incremental cost per case LBW prevented. Factors considered included HIV seroprevalence, placental malaria prevalence, LBW incidence, the cost of SP, medical care for LBW infants, and HIV testing. For a hypothetical cohort of 10,000 pregnant women, the monthly SP regimen would always be the most effective strategy for reducing LBW associated with malaria. The two-dose SP and monthly SP regimens would prevent 172 and 229 cases of LBW, respectively, compared with the case management approach. At HIV seroprevalence rates greater than 10%, the monthly SP regimen is the least expensive strategy. At HIV seroprevalence rates less than 10%, the two-dose SP regimen would be the less expensive option. When only antenatal clinic costs are considered, the two-dose and monthly SP strategies cost US $11 and $14, respectively, well within the range considered cost effective. Presumptive treatment regimens to prevent LBW associated with malaria and the subsequent increased risk of mortality during the first year of life are effective and cost effective strategies in areas with both elevated HIV prevalence and malaria transmission rates.

The burden of malaria in pregnancy in malaria-endemic areas

Pregnant women in malarious areas may experience a variety of adverse consequences from malaria infection including maternal anemia, placental accumulation of parasites, low birth weight (LBW) from prematurity and intrauterine growth retardation (IUGR), fetal parasite exposure and congenital infection, and infant mortality (IM) linked to preterm-LBW and IUGR-LBW. We reviewed studies between 1985 and 2000 and summarized the malaria population attributable risk (PAR) that accounts for both the prevalence of the risk factors in the population and the magnitude of the associated risk for anemia, LBW, and IM. Consequences from anemia and human immunodeficiency virus infection in these studies were also considered. Population attributable risks were substantial: malaria was associated with anemia (PAR range = 3-15%), LBW (8-14%), preterm-LBW (8-36%), IUGR-LBW (13-70%), and IM (3-8%). Human immunodeficiency virus was associated with anemia (PAR range = 12-14%), LBW (11-38%), and direct transmission in 20-40% of newborns, with direct mortality consequences. Maternal anemia was associated with LBW (PAR range = 7-18%), and fetal anemia was associated with increased IM (PAR not available). We estimate that each year 75,000 to 200,000 infant deaths are associated with malaria infection in pregnancy. The failure to apply known effective antimalarial interventions through antenatal programs continues to contribute substantially to infant deaths globally.

Malaria, intestinal parasites, and schistosomiasis among Barawan Somali refugees resettling to the United States: a strategy to reduce morbidity and decrease the risk of imported infections

In 1997, enhanced health assessments were performed for 390 (10%) of approximately 4,000 Barawan refugees resettling to the United States. Of the refugees who received enhanced assessments, 26 (7%) had malaria parasitemia and 128 (38%) had intestinal parasites, while only 2 (2%) had Schistosoma haematobium eggs in the urine. Mass therapy for malaria (a single oral dose of 25 mg/kg of sulfadoxine-pyrimethamine) was given to all Barawan refugees 1-2 days before resettlement. Refugees >2 years of age and nonpregnant women received a single oral dose of 600 mg albendazole for intestinal parasite therapy. If mass therapy had not been provided, upon arrival in the United States an estimated 280 (7%) refugees would have had malaria infections and 1,500 (38%) would have had intestinal parasites. We conclude that enhanced health assessments provided rapid on-site assessment of parasite prevalence and helped decrease morbidity among Barawan refugees, as well as, the risk of imported infections.

Efficacy of sulfadoxine-pyrimethamine for prevention of placental malaria in an area of Kenya with a high prevalence of malaria and human immunodeficiency virus infection

A fever case management (CM) approach using sulfadoxine-pyrimethamine (SP) was compared with two presumptive intertmittent SP treatment regimens in the second and third trimesters in pregnant primigravidae and secundigravidae in an area of intense Plasmodium falciparum malaria transmission in western Kenya. The investigation evaluated efficacy of the antimalarial regimens for prevention of placental malaria and examined the effect of human immunodeficiency virus (HIV) infection on antimalarial drug efficacy and adverse drug reactions. Twenty-seven percent (93 of 343) of pregnant women in the CM group had placental malaria compared with 12% (38 of 330; P < 0.001) of women who received two doses of SP and compared with 9% (28 of 316; P < 0.001) of women who received monthly SP. Fourteen percent (49 of 341) of women in the CM group delivered low birth weight (LBW) infants compared with 8% (27 of 325; P=0.118) of women who received two doses of SP and compared with 8% (26 of 331; P=0.078) of women who received monthly SP. Seven percent (7 of 99) of the HIV-negative women on the two-dose SP regimen had placental malaria compared with 25% (10 of 39; P=0.007) of HIV-positive women on the same regimen; the rate of placental malaria in HIV-positive women was reduced to 7% (2 of 28; P=-0.051) for women on the monthly SP regimen. Less than 2% of women reported adverse drug reactions, with no statistically significant differences between HIV-positive and HIV-negative women. Intermittent treatment with SP is safe and efficacious for the prevention of placental malaria in pregnant primigravidae and secundigravidae in sub-Saharan Africa. While a two-dose SP regimen may be effective in areas with low HIV seroprevalence, administration of SP monthly during the second and third trimesters of pregnancy should be considered in areas of high HIV seroprevalence to prevent the effects of maternal malaria on the newborn.

Malaria surveillance -- United States, 1994

PROBLEM/CONDITION

Malaria is caused by infection with one of four species of Plasmodium (i.e., P. falciparum, P. vivax, P. ovale, and P. malariae ), which are transmitted by the bite of an infective female Anopheles sp. mosquito. Most malarial infections in the United States occur in persons who have traveled to areas (i.e., other countries) in which disease transmission is ongoing. However, cases are transmitted occasionally through exposure to infected blood products, by congenital transmission, or by local mosquitoborne transmission. Malaria surveillance is conducted to identify episodes of local transmission and to adapt prevention recommendations.

REPORTING PERIOD COVERED

Cases with onset of symptoms during 1994.

DESCRIPTION OF SYSTEM

Malaria cases confirmed by blood smear are reported to local and/or state health departments by health-care providers and/or laboratories. Case investigations are conducted by local and/or state health departments, and the reports are transmitted to CDC through the National Malaria Surveillance System (NMSS), which was the source of data for this report. Numbers of cases reported through NMSS may differ from those reported through other passive surveillance systems because of differences in the collection and transmission of data.

RESULTS

CDC received reports of 1,014 cases of malaria with onset of symptoms during 1994 among persons in the United States or one of its territories. This number represented a 20% decrease from the 1,275 cases reported for 1993. P. vivax, P. falciparum, P. malariae, and P. ovale accounted for 44%, 44%, 4%, and 3% of cases, respectively. More than one species was present in five persons (<1% of the total number of patients). The infecting species was not determined in 50 (5%) cases. The number of reported malaria cases in U.S. military personnel decreased by 86% (i.e., from 278 cases in 1993 to 38 cases in 1994). Of the U.S. civilians who acquired malaria during travel to foreign countries, 18% had followed a chemoprophylactic drug regimen recommended by CDC for the area to which they had traveled. Five persons became infected while in the United States; the infection was transmitted to two of these persons through transfusion of infected blood products. The remaining three cases, which occurred in Houston, Texas, were probably locally acquired mosquitoborne infections. Four deaths were attributed to malaria.

INTERPRETATION

The 20% decrease in the number of malaria cases from 1993 to 1994 resulted primarily from an 86% decrease in cases among U.S. military personnel after withdrawal from Somalia. Because most malaria cases acquired in Somalia during 1993 resulted from infection with P. vivax, there was a proportionately greater decrease during 1994 in the number of cases caused by P. vivax relative to those caused by P. falciparum.

ACTIONS TAKEN

Additional information was obtained concerning the four fatal cases and the five cases acquired in the United States. Malaria prevention guidelines were updated and distributed to health-care providers. Persons traveling to a geographic area in which malaria is endemic should take the recommended chemoprophylactic regimen and should use protective measures to prevent mosquito bites. Persons who have a fever or influenza-like illness after returning from a malarious area should seek medical care; medical evaluation should include a blood smear examination for malaria. Malarial infections can be fatal if not promptly diagnosed and treated. Recommendations concerning prevention and treatment of malaria can be obtained from CDC.

Malaria surveillance--United States, 1993

PROBLEM/CONDITION

Malaria is caused by infection with one of four species of Plasmodium (P. falciparum, P. vivax, P. ovale, and P. malariae), which are transmitted by the bite of an infective female Anopheles sp. mosquito. Most malaria cases in the United States occur among persons who have traveled to areas (i.e., other countries) in which disease transmission is ongoing. However, cases are transmitted occasionally through exposure to infected blood products, by congenital transmission, or by local mosquito-borne transmission. Malaria surveillance is conducted to identify episodes of local transmission and to guide prevention recommendations.

REPORTING PERIOD COVERED

Cases with onset of illness during 1993.

DESCRIPTION OF SYSTEM

Malaria cases confirmed by blood smear are reported to local and/or state health departments by health-care providers and/or laboratories. Case investigations are conducted by local and/or state health departments, and the reports are transmitted to CDC.

RESULTS

CDC received reports of 1,275 cases of malaria in persons in the United States and its territories who had onset of symptoms during 1993; this number represented a 40% increase over the 910 malaria cases reported for 1992. P. vivax, P. falciparum, P. ovale, and P. malariae were identified in 52%, 36%, 4%, and 3% of cases, respectively. The species was not determined in the remaining 5% of cases. The 278 malaria cases in U.S. military personnel represented the largest number of such cases since 1972; 234 of these cases were diagnosed in persons returning from deployment in Somalia during Operation Restore Hope. In New York City, the number of reported cases increased from one in 1992 to 130 in 1993. The number of malaria cases acquired in Africa by U.S. civilians increased by 45% from 1992; of these, 34% had been acquired in Nigeria. The 45% increase primarily reflected cases reported by New York City. Of U.S. civilians who acquired malaria during travel, 75% had not used a chemoprophylactic regimen recommended by CDC for the area in which they had traveled. Eleven cases of malaria had been acquired in the United States: of these cases, five were congenital; three were induced; and three were cryptic, including two cases that were probably locally acquired mosquito-borne infections. Eight deaths were associated with malarial infection.

INTERPRETATION

The increase in the reported number of malaria cases was attributed to a) the number of infections acquired during military deployment in Somalia and b) complete reporting for the first time of cases from New York City.

ACTIONS TAKEN

Investigations were conducted to collect detailed information concerning the eight fatal cases and the 11 cases acquired in the United States. Malaria prevention guidelines were updated and disseminated to health-care providers. Persons who have a fever or influenza-like illness after returning from a malarious area should seek medical care, regardless of whether they took antimalarial chemoprophylaxis during their stay. The medical evaluation should include a blood smear examination for malaria. Malaria can be fatal if not diagnosed and treated rapidly. Recommendations concerning prevention and treatment of malaria can be obtained from CDC.

Bubonic leishmaniasis: a common manifestation of Leishmania (Viannia) braziliensis infection in Ceara, Brazil

Enlarged regional lymph nodes have been reported to accompany the cutaneous lesions of Leishmania (Viannia) braziliensis (= L. braziliensis). A survey in Ceara State, Brazil indicated that 77% of persons (456 of 595) with parasitologically confirmed cutaneous leishmaniasis reported lymphadenopathy in addition to skin lesions. A group of 169 persons with recently diagnosed leishmaniasis and lymph nodes measuring > or = 2 cm in diameter (mean = 3.6 cm, maximum = 10.5 cm) underwent detailed clinical examination. Lymphadenopathy preceded the skin lesions in more than two-thirds of these, on the average by two weeks. Cultures of lymph node aspirates yielded Leishmania more frequently (86%) than cultures of aspirates of skin (53%) or biopsies of skin (74%). Parasites were isolated from the peripheral blood of one patient. Persons with lymphadenopathy gave a history of fever and had enlarged livers or spleens more often than a comparison group of 50 persons with cutaneous lesions but no lymphadenopathy. Persons with lymphadenopathy had more intense leishmanin skin reactions and lymphocyte proliferation following stimulation with specific antigens, whereas persons without lymphadenopathy had a higher frequency of previous infection. Isolates of parasites from both groups were identified as L. braziliensis. These data demonstrate the early spread of L. braziliensis beyond the skin and suggest differences in host immunity between persons with and without lymphadenopathy. Leishmaniasis braziliensis should be considered in cases of unexplained lymphadenopathy in endemic areas.

Mosquito-transmitted malaria in New York City, 1993

In August, 1993, 3 cases of Plasmodium falciparum malaria in people without recent travel histories or bloodborne exposure were reported in New York City. An epidemiological investigation confirmed the absence of risk factors for acquisition of malaria in two cases. The third case could not be definitively classified as locally acquired malaria because the patient had travelled to Thailand two years before malaria was diagnosed. The 3 individuals lived in separate houses in the same neighbourhood of Queens, New York and had onset of illness within a day of each other. The investigation consisted of patient interviews, active case finding, reviewing recent New York flight and shipping arrivals, and an entomological survey for anopheline mosquitoes and breeding sites. No other cases were identified. The 3 patients lived several miles from air and sea ports and prevailing winds would have carried any mosquitoes at those sites away from the patient's homes. By the time of the environmental investigation (September, 1993), the area was dry and neither adult nor larval anophelines were found. However, weather conditions at the probable time of infection (July, 1993) were very different. Malaria was probably transmitted to these 2 patients by local anopheline mosquitoes that had fed on infected human hosts. Mosquito-control measures were not implemented because there was no evidence of ongoing transmission. The occurrence of mosquito-transmitted malaria in New York City demonstrates the potential for reintroduction of malaria transmission into areas that are no longer endemic and emphasises the need for continued surveillance and prompt investigations, if cases without risk factors are reported.